The purpose of the study is to identify cardiovascular risk factors, especially modifiable ones, associated with increased risk in very late onset cognitive decline, dementia, and Alzheimer's disease (AD). Unlike the recent rapid progress in the genetics of AD, there is virtually no definitively identified non-genetic risk factor for AD other than age. However, recent evidence suggesting cardiovascular risk factors may be associated with dementia and AD is highly intriguing not only because the widespread prevalence of such factors, especially in the very old, might plausibly account for a large proportion of cases, but also because many of them are modifiable. Hence if cardiovascular risk factors do indeed increase risk for dementia and AD, identifying them offers the prospect of real public health gains in this area. The search for such risk factors among the oldest old may be valuable because the incidence of AD and other dementias is at its peak in this group and genetic factors appear to play a minimal role suggesting that this group may be most likely to reveal other, potentially more tractable risk factors. The five year study will focus on a cohort of 520+ very elderly (mean age >85) non-demented residents of an apartment complex for the independent elderly (Kitay House) and an affiliated nursing home (Jewish Home and Hospital for the Aged [JHHA]). At Kitay House, in years 1-4, the Clinical Support Core will identify and assess non-demented residents who will be followed annually by the Core in serial assessments to determine the incidence of cognitive decline, AD, vascular and other dementias. Similarly, a smaller group of non-demented residents of the JHHA will also be ascertained and serially assessed. An aim of the project will be to collect cardiovascular risk factor information from these residents through a physician's physical examine and medical history, biological assays, chart review, and direct interviews. These data will then facilitate the testing of our hypothesis that these factors increase the risk of cognitive decline, dementia in general, and AD. An evaluation of these risk factors for mixed dementia and vascular dementia is also of interest, but these aims are subsidiary, because it is possible that the number of such cases may be small, providing limited statistical power.